(Sports Network) - Lefty Wandy Rodriguez aims to maintain a solid stretch of Houston pitching tonight when the Astros host the San Diego Padres in the opener of a four-game series at Minute Maid Park.

Houston pitchers allowed two or fewer runs for the fifth consecutive game on Sunday, as J.A. Happ (6-7) yielded a run on four hits in a 7-1 defeat of the Cleveland Indians to wrap up a three-game series.

Chris Johnson and J.D. Martinez both homered in a four-run eighth inning for the Astros.

Rodriguez, a double-digit winner in each of the last three seasons, picked up win No. 6 of 2012 on June 14 with a 6-3 defeat of the San Francisco Giants at AT&T Park.

He allowed three runs on six hits in six innings in the victory, which included two walks and three strikeouts and raised his road record to 3-1 in six starts.

In one subsequent outing, he gave up two runs on six hits in seven innings of a tough-luck 2-0 home loss to interleague foe Kansas City on June 19.

In six career meetings with the Padres, Rodriguez is 3-2.

San Diego got a mound gem of its own on Sunday, when Edinson Volquez tossed 6 2/3 scoreless innings in a 2-0 defeat of the Seattle Mariners in the finale of a three-game interleague series at Petco Park.

Volquez (4-7) allowed four hits with three walks and four strikeouts to notch the win. Joe Thatcher got the final out of the seventh, Luke Gregerson pitched a scoreless eighth and Huston Street recorded his 10th save of the season with a clean ninth inning.

Alexi Amarista provided the only offense of the day with a two-run, ground- rule double for the Padres, who had lost four of their last five contests. Mark Kotsay went 3-for-3 in the triumph.

Journeyman righty Ross Ohlendorf makes his fourth appearance and second start for the Padres since signing as a free agent on June 4.

The 29-year-old was a fourth-round pick of the Arizona Diamondbacks in 2004 and debuted with the New York Yankees in 2007 after being part of the offseason deal that sent Randy Johnson back to Arizona.

He was sent to Pittsburgh in a six-player trade in 2008, then signed with the Boston Red Sox in February after the Pirates released him at the end of 2011.

Ohlendorf made 10 starts at Triple-A Pawtucket this spring before being granted free agency and heading to San Diego.

He allowed seven hits and two runs in relief outings against San Francisco and Milwaukee on June 7 and 9, then started for the first time and allowed three runs on five hits in 4 2/3 innings of the Padres' 6-4 loss at Oakland on June 16.

In 11 career meetings with Houston, Ohlendorf is 0-6 with a 5.89 earned run average in 47 1/3 innings.

The Padres won five of eight games with the Astros in 2011 and five of seven in 2010. Houston last won the season series between the teams in 2009, taking six of seven games.